1. Field of the Invention
The present invention relates, in general, to a technology for vehicle-location recognition and vehicle assembly-history is management and, more particularly, to a vehicle-location recognition system and method and a vehicle assembly-history management system and method using the same, enabling precise assembly history management without tags for location recognition of vehicles, irrespective of a worker's working location and his position in the sequence of assembly processes.
2. Description of the Related Art
As the competition between car manufacturers in the global car market intensifies, more emphasis is being placed on the quality of respective manufacturers' cars. In particular, cars that exhibit low durability are generating very little interest in the market.
In addition, assembly operations that are carried out in most manufacturing lines and processes for manufacturing cars are operations that are directly relevant to the durability of finished cars. At present, workers responsible for respective processes carry out the assembly operations using pneumatic tools, electric tools, or the like.
Each pneumatic or electric tool has an assembling torque value which is set by a tool controller, such that when a worker presses an operating button of the tool, the tool carries out an assembling operation with the assembling torque value that was set.
However, the set assembling torque value does not always coincide with the value of the torque actually applied during assembly, and particularly, even if the assembling torque value is precisely applied, the value of the torque actually applied during assembly may not satisfy quality standards due to operational errors of the tool controller, a worker's mistake, or the like.
Thus, advanced automobile manufacturers record and manage actually applied assembling torque values by grafting various sensing technologies onto assembling tools in order to ensure durability of a vehicle.
FIG. 1 shows an assembly history management system for vehicles according to the related art, which manages a history of assembly operations by matching the actually applied assembling torque values with target cars using an RFID system.
That is, when a vehicle having an attached RFID tag 1 passes by a process section in which an RFID sensor 2 is installed, the history management system reads out the RFID tag 1 to identify an ID number of a vehicle that is passing by the process section. Next, the ID number of the vehicle that is positioned in the current assembling process section is inferred using the sequence number from a list of vehicle ID numbers. Hence, when a worker carries out an assembling operation, the system matches the inferred ID number with an actually applied assembling torque value transmitted from a tool controller, and stores the corresponding data.
However, in the conventional technology, it is required that a worker has to carry out an assembling operation within a defined assembling process section. If the worker carries out his assembling operation out of the defined assembling process section, an inferred target object and an actual target object do not coincide with each other, and the precise management of assembling history is therefore lost. In an actual assembling environment, workers often carry out their assembling operations outside of a defined assembling process section, so it is not possible to precisely manage a history of assembling operations.
Korean Unexamined Patent Publication No. 10-2008-054264 describes a vehicle management method using RFID and a computer-readable recording medium recording a program therein for implementing the management method. However, the above technology has a problem in that, because tags have to be attached to all vehicles, a tag-attachment process has to be separately added, and battery-charging states of tags have to be periodically checked and if needed, tags have to be replaced.
The description regarding the related art is provided only for understanding of the background of the invention, so it should not be construed by ordinarily skilled persons in the art to be admitted to be the related art.